Insulator



F. H. MILLER Dec. 30, 1930.

INSULATOR Filed June 16, 1928 3 INVENTOR Frederic H. Miller.

A'TTORNEY Patented Dec; 30, 1930 UNITED STA FBEDERIdI-I; Ermine, or w LxI vsBUizG, PENNsYLVAnIA, AssIGnoR 'ro WESTING- nonsn ELncr rc s vmNUrAcrUR nG COMPANY, A CORPORATION or PENNSYL- ,YANIA j inseam; filed a e,

, My'inventi'on relates to insulators andparticularly to high-voltage insulators for transmission-line service. i

One object of my invention is to provide an insulator embodying'a load-element andan enclosing casing therefor in which a complete hermetic seal for the casing shall be obtained by the use of a singlesealing joint only;

Another object of my invention is to provide an insulator embodying an enclosed load- 5 character of the device;

element in which a single integral end-closure member for the enclosing means shall be so interposed between the load element and a terminal member as to improve the sealing Another object of my invention is to provide an insulator structure involving the use of a seal, such as a solderseal, in which the seal may be advantageously and effectively 0 formed by pouring, in contradistinction to seals that are wip'edin placeor effected by other'methods.

Anotherobject of my invention is to provide an insulator embodyinga load element, terminal members on the element and an insulating tube about the element in which, by providing for attachment of the terminals to the load element after placing the element in the tube,-the latter may be'o'f smaller diameter 30 than having the terminals attached to the "fl sembly of an insulator-ref a .type heretofore suggested. v i A further object of myinvention'is to pro- .vide a'lhigh-voltage insulator that shall be simple and durable in construction, economical to manufacture and effective inits opera tion.'

In co pendingi application, Serial No.

285,938, filed June 16, 1928,-by myself and- R. P. J acks'on, is disclosed an insulator of the' general type herein setjforth, to which referitconducting.

., meeting v Serial Ito. 235,939.

enceniay be had'for a better understanding of'thepresent invention. I

Theidevice embodies the principle of providing a composite insulator of organic and inorganic materials, utilizing the superior mechani'calstrengthof the organic material to support the load and -the' weather and co- 'rona 'resisting properties of the inorganic material to protect the organic material.

" Insulators 'of this general classification have been suggested before, but, in none of them,aside from that of the above-mentioned co-pending application, so far as I am aware,

has a seal of sufiicient tightness or durability been provided to-permitthe same to be used,

except in special applications, as will herein after appear.

Insulators have been suggested which individually embody a load-sustainingelement of rope, impregnated paper or cloth, woodand otherorganic material surrounded by aninorganic tube o1 porcelain, glass and 'the like,

the'purpose being to protect the organic element'against the weather or corona, both of which very seriously adversely affect the organicelement. I

However, despite this precaution,corona has a strong tendency to creep along the organic element to ultimately char and render Gummy or hardening filling materials between the tube andthe load element, when poured into the tube while hot, shrinkaway from 'Ethe' parts upon cooling and thereby provide fissures or spaces through which corona creeps;

An'insula'tor employing-oil has been em- 'ployed but, with-the best known standard I sealing meansflreadily available and known to the art, the oil has a strong propensity to seepthrough any'ordinary seal and to evaporate where it is not'absolutely hermetically sealed. I This insulator, employed only in very special service, such askat long rivercrossing spans, is provided with oil gauges so that an operator may inspect the same from the ground, by the use of binoculars, and

mount the tower to refill the insulator when such attention is not well adapted for general use along a line.

In the device of the present invention and that of the co-pending application, the tube is effectually sealed, by fusing or integrally uniting porcelain and metal to each other as though both of these materials were of metal, to provide a permanent, durable hermetic seal not requiring attention to the insulator or renewal of the insulating fluid over long periods of time.

In the above-mentioned co-pending application, the seal is effected by the use of two molecular joints at each end of the tube and further, the tube is of sufficient diameter to pass over the tension element with the terminal attaching means of the latter in place.

It is my aim to provide an improved insulator in which onlyone-seal is required at each end of the tube, in which the tube may be of smaller diameter and in which other advanced features of construction, manufacture, assembly, cost and operation shall be present.

Accordingly, in practicing my invention, I provide an insulator in which the load-element terminals are so mounted after the reception of the tube, in which a single integral closure element for the end of the tube is so placed between the load element and its terminal, and in which a single seal and other features are incorporated, as to obtain all of the purposes of my invention and an insulator that is, in general, an advance in the important art to which it relates.

Figure 1, of the accompanying drawing is alongitudinal side View, partially in elevation and partially in section, of an insulator constructed in accordance with my invention,

Fig. 2 is a sectional view of the upper portion of the structure shown in Fig. 1, taken at right angles thereto,

Fig. 3 is a sectional view taken along the line III-III of Fig. 2, and

Fig. 4 is an enlarged detail sectional view of a portion of the device shown at the upper left-hand side of Fig. 1. p

The device comprises, in eneral, a loadsustaining element 2, a tubular enclosing member or casing 3 therefor and upper and lower terminal structures 4 and 5, respectively.

The load-sustaining element 2 is preferably a tension element, in the formof a rod or tube, and constructed of organic or fibrous insulating material, such as wood, paper, cloth or other fiber impregnated with a preserving, hardening, sealing or strengthening binder, a referred form being that of "a wood strain ro impregnated by any suitable ma- 'terial, such 'as 'alurite', to preserve, seal, strengthen or protect the'sanie.

The rod 2 may be slightly convergingly tapered from it's mid portion and have enlarged substantially frusto-conical ends 7 to provide strength and effective distribution of the load.

The tubular casing 53, of inorganic material, preferably porcelain, is provided with a silica-glaze coating 10, as indicated more clearly in Fig. l, and, on its outer longitudinal surface, adjacent to its ends, with metallic-glaze bands or coatings 12. Other arrangements of the coatings 10 and 12 are contemplated, such as omitting the silica glaze from certain parts of the tube and placing the metallic glaze on the transverseend, or inner longitudinal, surfaces of the tube 3.

In providing the coatings 12, the initially vitrified and silica-glazed tube 3 is coated with the metallic glaze in a wet state and the tube again subjected to a firing operation which is at a temperature suitable to fuse the silica glaze, after which it is slowly cooled to room temperature.

The metallic glaze employed is preferably chloro-platinic acid suspended in essential oils, such as lavender, cloves and spice, the result being a lustrous silvery metallic surface which is integrally united molecularly to the silica glaze and, through the latter, to the tube and which may be soldered, electroplated and otherwise treated or integrally united molecularly to other metals.

The union between the metallic glaze and the tube is so close that, when the metal coating is forcibly torn from the tube, particles of the porcelain are torn off with it.

This structure distinguishes from coatings produced by the deposition of the so-called sticky materials, the electrolytic deposition of metals, the spraying of molten metals and other processes which do not ordinarily produce bands comparable in strength, durability or fluid and vacuum tightness to the band above set forth.

Other compounds or mixtures which may be applied in a manner similar to chloroplatinic acid to obtain the metal-surface coatings 12, are silver nitrate mixed with a reducing agent, such as sugar, silver oxalate; copper acetate, niekel formate, copper formate and any other metal which may be reduced.

End caps 14, preferably of sheet material. such as copper, and each consisting of one integral or homogeneous piece, fare diepressed, spun or otherwise formed tohave initially cylindrical central cup portions 15 of sufficient diameter, at the mouths thereof, to pass freely over 'theyenlarged outer ends of the 'frusto-conical portions of the ten-- sion "element 2. The cups '14 further comprise laterally-extending portions 17 and downwardly-and=outwardlyextending 1 portions 18, the portions 17 providin a certain amount of longitudinal yieldab e support for the tube andthe portions '18 forming,

This construction compensates for thermal-expansion andload-stress movement between the rod 2 and the tube 3 and permits the solder bodies 19 to be poured into position rather than having to be wiped, as is usual in making wiped joints, or provided in other complicated and expensive manner. In pouring the solder bodies 19, the bottom .body is poured first and the structure then inverted for pouring the other solder body.

The tube 3 is thus sealed, at each end, by a single integral member through the medium of a single sealing joint only, which is made with facility and economy.

After being thus sealed, a body 22 of oil or other insulating medium is admitted to the tube 3 around the element 2 through a small opening in one of the end caps 14 which is hermetically sealed, as by a body of solder 20, indicated in Fig.4.

The terminal structures 4 and 5 further comprise complementary clamping members 23 having fru'sto-conical inner clamping surfaces and laterally-extending apertured. lugs 2a which, by the aid of bolts 25 and nuts 26, are laterally clamped in longitudinal interlocking relation to the sides of the cup portions 15 of the sealing cups 14 and the frusto-conical ends 7 of the load element 2. Thus, the load is transferred from the outer ends of the insulator, through the intermediary of the cups 15, to the tension element, leaving the inorganic tube 3 substantially free of the load.

The clamping members 23, in'clamping position, longitudinally interlock with terminal bolts 28 and 29 for the reception of clevis and eye members 30 and 31, respectively, or other suitable members for mountingthe insulator, as a whole, on a tower or other main support and attaching a conductor clamp to the insulator.

Means for sealing the spaces between the upper clamping members 23 and thereby preventing moisture from traversing the outer surface of the tube 3 is provided in the form of a hood or cap 33 that isv disposed over the clamping members 23 and held in place by a washer 34 and the clevis 30.

The clamping members 23 further comprise end-web portions 35 and side web portions 36 which, with the clamping lugs 2 1 thereof fit the inner surfaces of the hood 33.

The lower terminal structure 5 is similar to the upper terminal structure 4. for facility of manufacture and assemblybut, in this case, the hood portion 33 does not function as does the corresponding portion of the upper terminal. a a o In the lower terminal structure, means is provided, as in the form of an opening 37 in one of the transverse web portions 35 of one of the clamping members 23 and in the end wall of'the hood 33, to drain moisture from the lower hood Bot-h hoods 33 have radially extending inner flanges 38 to the upper of which an elec- 'trostaticsstress-distributor and weather-pro tecting hood member 39 and to the lower of which a cooperating stress-distributing torus 40'may be secured, as by rivets 42.

'Theflange 38 of the upper terminal is disposed over the inn'eredge portion of the hood inember 39 and sloped outwardly and down;

wardly to prevent the admission of moisture at this position. 1 i

Also, adjacent annular edges 44 and 45 of the members 39 and 14:,respect1vely, are pref- I erably. arranged in substantially concentric flush relation to preserve the continuity of the undersurfaces thereof.

lVhile I have shown and described a particular form of my invention, changes may be effected therein without departing from the spirit and scope thereof, as set forth in the appended claims.

I claim as my invention 1. An insulator comprising a load-sustaining member embodying an element of or ganic dielectric material, a tubular element of inorganic dielectric material surrounding the same, an end member entirely closing, and integrally united molecularlyto, an end of the tube through a single sealing joint only and a terminal member for said load member and cooperating therewith through the intermedlary of'said end member, said end memher being ofmetal and having a portion permitting relative movement between the load member and the tube.

2. An insulator comprising a load-sustainmg insulating membena tubular member surrounding the same, an end-closure member for the tube having a substantially cup portion for an end of said load member and a terminal structure for the load member dis-v posed 1n transverse gripping relation to said cap and to said end of the load member.

.An insulator comprising a load-sustaining insulating member having an outwardlyflaring'substantially frusto-conical end, a tubular member surrounding said member, a sheet-metal end closure member for the tube having a cup portion disposed over, and sub stantially conforming'to, said frusto-conical end and a terminal structure for the load member including a plurality of clamping members. for transverse clamping relative to said cup portion.

4. An insulator comprising a load-sustaining insulating member, a tubular member surrounding the same, a relatively-thin sheetmetal end-closure member for the tube hav 3 ing a cup portion for an end of said load memberand an annular yieldable portion between the cup portion and the tube, and a terminal structure for the loadmember dis-. posed intransverse gripping relation to said cup and to said end of the load member.

An insulator comprising a load-sustaining insulating member, a tubular member surrounding the same, a relatively-thin sheetmetal end-closure member for the tube having a cup portion for an end of said load member and an annular yieldable portion between the cup portion and the tube, and 'a terminal structure for the load member dieposed in transverse gripping relation to said cup and to said end of the load member in lon 'itudinal spaced relation to said annular yieldable portion.

6. An insulator comprising a load-sustaining insulating member, a tubular member surrounding the same, an end-closure member for the tube having a cup portion for an end of said. load member, a terminal structure for the load member including a plurality of clai'n iing members for transverse clamping relation to said cup portion, and means for preventing the passage oi moisture between said clampin members.

7. An insulator con'iprising a it d-sustaining insulating member, a tubmar member surrounding the same, an end-cl sure mem her for the tube having a cup portion for 2: end of said load member, a teen n. tructure for the load member inc. rality of clamping members for transverse clamping relation to said cup portion, and means constituting a hood over said clamping members.

8. A11 insulator comprising a l.oa ;l-sustaining insulating member, an insulating eienient surrounding the same and having an opening, a single integral member sealed to said element and entirely enclosing said opening, and a terminal member for said load member in cooperating therewith tln'ough the intermediary of said enclosure member, the latter having a portion permitting relative movement between the load member and said eie ment.

In testimony whereof, I have hereunto subscribed my name this 9th day of June, 1928.

FREDERIC H. MILL *R. 

